An ultrasound system has become an important and popular diagnostic tool since it has a wide range of applications. Specifically, due to its non-invasive and non-destructive nature, the ultrasound system has been extensively used in the medical profession. Modern high-performance ultrasound systems and techniques are commonly used to produce two-dimensional (2D) or three-dimensional (3D) ultrasound images of internal features of an object (e.g., human organs).
The ultrasound system may provide ultrasound images of various modes including a brightness mode (B mode) image representing reflection coefficients of the ultrasound signals reflected from a target object of a living body with a 2D (two-dimensional) image, a Doppler mode (D mode) image representing speed of a moving object with spectral Doppler by using a Doppler effect, a color Doppler mode (C mode) image representing speed of a moving object with colors by using the Doppler effect, and an elastic mode (E mode) image representing mechanical characteristics of tissues object before and after applying a pressure thereto. In particular, the ultrasound system may transmit and receive ultrasound signals to and from the target object to thereby form Doppler signals corresponding to a region of interest (ROI), which is set on a B mode image. The ultrasound system may further form a C mode image that represents the speed of the moving object with colors based on the Doppler signals.
The ultrasound system may transmit and receive ultrasound signals to and from the living body at a predetermined period to acquire ultrasound data corresponding to an ensemble number (i.e., ensemble data). The ultrasound system may further form the Doppler signals based on the ensemble data. The ultrasound system may also perform a wall filtering process to remove a component corresponding to a tissue, which does not move, upon the Doppler signals based on a wall filter to form the C mode image. However, it takes a lot of time to acquire the ensemble data. Further, when a size of the ROI (i.e., a color box) is large, the frame rate of the C mode image is decreased.